The Owner Manual included with the DTX400 series has the same 10 basic 2-measure beats as SONG BEATS on pages 62 and 63. You can get a PDF version from the link below.
The DTX400 songs are the same ones as the ten Demo Songs in SONG BEATS. The PDF score for these songs is available at the link below.
As for the songs you download from within the app, these are midi song files that can be opened in various music software applications, including Cubase, Sibelius, etc. Some of these programs have a "score view" which will create as best it can a notated version that may then be printed out. If you don't have any experience in this there are probably some local musicians who could help you if you ask around.
Good Luck and Happy Drumming!